Organic Light Emitting Diode (OLED) display is a self-luminous display device. Compared with a Liquid Crystal Display (LCD), an OLED display does not need a backlight, so an OLED display can be made thinner and lighter. In addition, an OLED display also has advantages such as high brightness, low power consumption, wide viewing angle, high response speed, wide temperature range, and is used more in a variety of high-performance display applications.
In related arts, thin film organic encapsulation is often employed to ensure that organic luminescent materials and electrodes are not eroded by water vapor and oxygen in the external environment. Meanwhile, in order to avoid an increase of unavailable areas at the periphery of the device caused by an extension of the thin film encapsulation layer, a retaining wall is typically provided surrounding the organic light-emitting structure in the related arts. In order to cover foreign materials on the surface of the substrate and still keep the substrate flat, the organic layer of the thin film encapsulation generally has a very thick film structure. The thin film encapsulation layer forms a step and a slope at the edge of the retaining wall. The metal wires tend to drop over the retaining walls. As a result, wires can fracture and signal transmission can be affected.